The proposed project consists of a continuing study of the effects of alterations in polycyclic hydrocarbon hydroxylase activity on carcinogenesis resulting from polycyclic hydrocarbon carcinogens and also of factors which effect the level of activity of these hydroxylases. The main emphasis during the current year will be on the isolation and identification of inducers of increased aryl hydrocarbon hydroxylase activity present in members of the Brassicaceae family. In addition, efforts will be made to develop procedures for quantitating the amounts of these compounds present and to determine factors which alter their concentration in plant material.